DETERMINATION OF SAMPLE-SIZE IN-SERVICE INSPECTION

When performing inservice inspection on a large volume of identical co mponents, it becomes an almost impossible task to inspect all those in which defects may exist, even if their failure probabilities are know n. As a result, an appropriate sample size needs to be determined when setting rtp an inspection program. In this paper, a probabilistic ana lysis method is employed to solve this problem. It is assumed that the characteristic data of components has a certain distribution which ca n be taken as known when the mean and standard deviations of serviceab le and defective sets of components are estimated. The sample size can then be determined within an acceptable assigned error range. In this way, both false rejection and acceptance can be avoided with a high d egree of confidence.